The announcement that Facebook is buying messaging service WhatsApp in a $19 billion deal has a lot of people asking, “What’s WhatsApp?” Here are 10 things to know about the social network’s latest acquisition.

1. The basics: WhatsApp is an app that can be downloaded to major smartphones that allows users to send and receive text, image, audio and video messages using Internet data plans, allowing the user to bypass his or her phone’s standard messaging system and any costs for using it.

2. Downloading WhatsApp is free for the first year, but costs users $0.99 per year after that.

3. Boasts 450 million monthly users, and 70 percent of them use it daily, according to The Associated Press. One million new users join each day. WhatsApp users send 19 billion messages and receive 34 billion messages each day, along with 600 million photos and 100 million video messages.

4. Its founders have street cred: WhatsApp was founded by Jan Koum, a former operations manager at Yahoo, and Brian Acton, a former Yahoo vice president of engineering. Koum came up with the idea in 2009 after leaving Yahoo years prior and brought in Acton, who had also recently left the company, according to a Gigaom profile.

5. The messaging feature was secondary at first: The app was originally envisioned as a service that would allow people who can’t get a hold of you to see your status. WhatsApp took off when it added the messaging feature in late 2009, according to Gigaom.

6. Doesn’t have ads: In a blog post, Koum wrote that the company charges so it doesn’t have to use advertising, something he and Acton grew a distaste for in their experience with Yahoo. “Remember, when advertising is involved you the user are the product,” Koum wrote. “At WhatsApp…[y]our data isn’t even in the picture. We are simply not interested in any of it.”

7. The courtship lasted years: Facebook founder Mark Zuckerberg first met with Koum in early 2012 for coffee at a German bakery in California, according to Bloomberg. The meeting spurred a friendship and frequent dinners and hikes. After talks of a deal grew serious, Koum signaled his final decision by showing up at Zuckerberg’s house on Valentine’s Day with chocolate covered strawberries.

8. Koum’s family immigrated to the U.S. from Ukraine when he was 16, and when he was growing up, they relied on food stamps from a distribution site near the Mountain View office he now occupies, according to Wired. The experience, including the high cost of calling home, influenced his conception of WhatsApp, which he wanted to be decidedly un-Soviet.

9. The company doesn’t store users’ data, so there would be nothing to give if the government came calling, the founders say. “We have encryption between our client and our server. We don’t save any messages on our servers, we don’t store your chat history. They’re all on your phone,” Koum told Wired.

10. Acton is a graduate of Stanford, where he got a degree in computer science, according to Wired. He grew up in suburban Florida, where his adoptive father attempted a professional golf career and his mother established an air freight business. He was the 44th employee of Yahoo.